OK, the name of this recipe is a little offensive to shrimp, but the real reason we call this a "cheaper" crabcake is because of the tofu. When puréed, it becomes a less-expensive filler for the cake batter of any type you want to make, and hey, shrimp is definitely cheaper when crabs are out of season. Don’t be turned off if you don’t like tofu — you can’t even tell it’s there, trust me — and for tofu lovers, it adds the perfect, velvety texture that only a tofu-eater would recognize.
Add the shrimp to the bowl of a food processor and blend the shrimp by pulsing 8-10 times. (Do not hold the button down, because the consistency of the shrimp will be too fine — you want nice big chunks in your shrimp cakes.)
Remove the puréed shrimp from the processor and add to a large bowl. Add the tofu to the bowl of the food processor and purée (for this, you can hold the button down). Add the tofu to the bowl with the shrimp. Next, add the parsley, breadcrumbs, and egg and stir well. Add the juice of 1 lemon and season with salt and pepper, to taste. Refrigerate until ready to use.
In a shallow bowl, add about ¼-½ cup breadcrumbs. Form the batter into small, 2-by 2-inch circular patties and dredge in the breadcrumbs. Place the breaded cakes on a sheet pan or plate and allow to rest in the refrigerator for at least 10 minutes to set up.
In a large sauté pan, heat the oil over medium-high heat. Add the shrimp cakes and cook until golden brown on both sides and cooked through, about 5 minutes per side. (Moderate the heat while you're frying the cakes so that it doesn't get too high and so the shrimp cakes don't burn.)
Meanwhile, mix together the mayonnaise, mustard, and remaining lemon juice. Season with pinch each of salt and pepper, and serve alongside the shrimp cakes.